M: I have one and a quarter pounds of boneless filet of sirloin steak and some tostadas. I'm trying to figure out how to combine those for lunch or an early dinner. You got any suggestions?
G: Absolutely. With sirloin filet and tostadas, I'd probably lean toward one of three directions depending on how much work you want to do.
This is the obvious answer, but it's obvious for a reason.
Sirloin filet is lean enough that a quick sear works very well here.
If you have some combination of:
Give the steak a 30–60 minute marinade.
Cook hot and fast, chop into small pieces, and pile onto tostadas with onion and cilantro (assuming your cilantro allergy doesn't apply to someone else in the house—otherwise parsley can actually work surprisingly well).
This gets closer to street-taco territory.
This is the one I'd probably make for myself.
Basically a hybrid between nachos and tostadas.
The advantage is that sirloin filet can sometimes feel a little too "proper" on a tostada. Melting cheese underneath ties everything together.
Given our previous ice-cream-Wellington discussion, I feel obligated to mention this.
It's basically:
Not a Wellington, but clearly related to the same family tree.
If you tell me what else is in the refrigerator—cheese, onions, peppers, mushrooms, eggs, lettuce, salsa, avocado, etc.—I can probably come up with something more specific than "put steak on tostada." The mushrooms answer in particular can get surprisingly interesting if you've got them.
M: Sorry, one piece of information I didn't give that's part of the reason why I came to you. It's a thick cut, so the idea of just giving it a sear seems like it would be a poor way to address the cut. This is like a couple inches thick at its thickest point, so it seems like either a somewhat slow cook or pre-cooking preparation would be necessary in a way that a thinner cut wouldn't require.
G: Ah, yes. When you said "boneless filet of sirloin," I pictured something in the 1-inch range. If you've got a thick sirloin filet that's approaching 2 inches or more, then the steak itself becomes the main event and the tostadas become the sidekick rather than the delivery vehicle.
For a thick cut, I'd strongly consider one of these approaches:
Probably my first choice.
You get a much more even interior than trying to brute-force it in a skillet.
Then:
This gives you the best steak and still lets the tostadas participate.
Another possibility is not putting the steak on the tostadas at all.
Make:
People build bites as they go.
Think more like Korean BBQ or fajitas than tacos.
A good thick sirloin filet can be nice enough that burying it under lettuce, salsa, and cheese feels a little wasteful.
Sirloin likes butter.
While the steak rests:
Slice the steak and serve it over tostadas spread with refried beans, then spoon some mushrooms and onions over top.
That feels more like a restaurant entrée than a taco.
One question: when you say "couple inches thick," do you mean a single steak weighing the full 1¼ pounds, or is it 1¼ pounds split among multiple filets?
A single 1¼-pound sirloin filet is getting into "roast-like" territory, where my advice changes substantially. If it's two or three thick filets, I'd still be firmly in the reverse-sear camp.
M: It looks like it's a couple pieces. I don't dislike the idea of the reverse sear, although I'd like to know about how long it would need to go in there if I was going for the 125. But I would appreciate it if you'd go online and see if there's any creative combinations outside of what you've described that would be easily accessible in terms of materials required that would combine the sirloin and tostadas in an unexpected way. If not, I'll salt it now and see if I can get it done for around 2 or 3, which is why I was asking about the amount of time, because it's what, 10 o'clock or so here? So if I salted it now, gave it an hour or two, I could get it done for like 2 or 3 o'clock, as long as the reverse sear oven time isn't excessive.
G: If you salt it now, you're in excellent shape for a 2–3 PM meal.
For a thick sirloin filet, I would actually prefer:
For steaks in the roughly 1.5–2 inch range, most reverse-sear references land in the neighborhood of 45–55 minutes at 250°F, though thickness and oven accuracy matter enormously. A thermometer is far more reliable than a clock. citeturn0search9turn0search18turn0search22
One thing I found interesting while looking around is that most steak-tostada recipes are surprisingly conservative. They largely boil down to:
The more interesting ideas come from stealing concepts from other dishes.
This is the one that jumped out at me.
Basically a roast-beef sandwich that forgot to bring the bread.
This is the closest thing to your Wellington challenge.
Several tostada recipes pair beans and mushrooms successfully. citeturn0search14
I'd do:
The tostada provides the crunch that puff pastry normally would.
This is the most unusual idea.
Instead of putting toppings on the tostada:
The tostada softens in places but stays crunchy in others.
Think "nachos that went to college."
Since you're talking about a late lunch / early dinner:
This has the advantage that a good thick sirloin filet can remain the star instead of being chopped into taco meat.
Assuming a reasonably stocked American refrigerator:
That uses the tostada as a structural element rather than a vehicle for taco toppings, and it feels like something you'd get at a restaurant rather than something assembled because "I have steak and tostadas."
Given your description of the steak, I'd focus on preserving the experience of eating a nice thick cut. The temptation with tostadas is to dice everything into little cubes. I think the better route is to cook the sirloin properly, slice it thin after resting, and let the tostada provide crunch underneath rather than trying to turn the steak into taco filling.